Anode support for cathodic protection system



y 20, 1965 H. w. HOSFORD, JR 3,196,101

ANODE SUPPORT FOR GATHODIC PROTECTION SYSTEM Filed Sept. 21, 1962INVENTOR. HARRY W. HOSFORDMR) WWW ATTORNEYS United States Patent 03,196,191 ANGDE UPE GRT FOR (IATHQBIC PRQTECTION SYSTEM Harry W.Hester-d, In, 2555 Strattord Road, llleveland 18, Qhio Filed Sept. 21,1962, Ser. No. 225,241 8 Claims. (ill. 204-196) This invention relatesin general to cathodic protection systems and more specifically to novelmeans for supporting anodes for the same.

Cathode protection systems for water tanks are well known and generallyinclude elongated anodes of aluminum or graphite, for example, which aresuspended in the large steel water tanks to prevent corrosion of thetanks. A proper voltage is maintained between the anodes and the tank toprevent solution of the iron. The anodes are generally in the form oflong rods or bars and are suspended in any suitable manner from the roofof the tank, the anodes of course being out of contact with the walls ofthe tank. Since the elongated anodes are preferably of suificientdiameter to provide long life and suitable current conductingproperties, they are relatively heavy and in the case of graphiterelatively fragile.

The anodes, of course, corrode and gradually disintegrate during use inperforming the intended object of preventing solution of the steel tankwalls. This corrosion and disintegration of the anodes not onlynecessitates periodic inspection and the eventual withdrawal andreplacement of the disintegrated anodes but also often times adverselyaffects the withdrawal of water from the tanks. The disintegration ofthe anodes results in pieces of the anodes dropping to the bottom of thetank, where upon such fragments have a tendency to clog the water pipeswhich effect the withdrawal of the Water from the tank.

It is accordingly desirable to prevent to the extent possible,commensurate with maintaining adequate contact area of the anodesurface, the disintegration of the anode and the resultant dropping ofthe disintegrated pieces to the tank bottom. "arious means have beenemployed without particular success, however, to achieve such result,such means generally not satisfactorily inhibiting the undesirabledisintegration.

With the above in mind, it is a primary object of the invention toinhibit or deter disintegration of the anodes by providing a novel anodesupport for partially enclosing and/or supporting the anodes insuspended manner in the tank.

It is a further object of the invention to provide an anode support thatdoes not materially reduce the water contact area of the anode surface.

Still another object is to provide an anode support that tightlycontacts the anode and which is flexible for maintaining such tightcontact upon change in shape of the anode.

Other objects and advantages of the present invention will becomeapparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawings setting forth in detail certain illustrativeembodiments of the invention, these being indicative, however, of but a.few of the various ways in which the principle of the invention may beemployed.

In said annexed drawings:

FIG. 1 is a side elevational view of a steel water tank havingassociated therewith the anode support means of the invention;

FIG. 2 is an enlarged fragmentary vertical cross-sectional view of suchtank showing a plurality of elongated anodes and support means thereforsuspended from the tank roof;

FIG. 3 is an enlarged detail view of the anodes and anode supportsillustrated in FIGS. 1 and 2;

FIG. 4 is an enlarged detail View showing an alternative method ofemploying the anode support comprising the invention; and

FIG. 5 is an enlarged detail view showing an anode support associatedwith a constant diameter anode assembly.

Referring now more particularly to the drawings, wherein like referencenumerals are used to indicate like parts, and particularly to FIGS. 1and 2, a conventional water tank or tower is generally indicated at 1%.Communicating with the bottom of the tank ill is a riser 12 forconducting water from or to the tank. The tank is supported in the usualmanner by legs 14.

In order to prevent corrosion of the tank 1%, anode assemblies generallyindicated at 16 are suspended from the roof of the tank it) by means ofeye bolts 18, the latter being mounted on transverse bars 21%} which arein turn mounted on the interior sides of covers 22, the covers 22;serving to close corresponding access openings in the top of the tank.The anode assemblies, which will be more specifically described below,include electric submarine cables 24 which lead to a common junction box26 on the roof of the tank. The junction box 26 is electricallycommunicative with a rectifier housing 28, the rectifier disposedtherein providing a pulsating direct current to the cables 24. In awell-known manner that forms no part of the present invention, a propervoltage is maintained in a circuit including the anodes, the rectifier,tank and water to prevent solution of the iron of the tank.

With the exception of the specific construction of the anode assemblies16 which form the present invention, the above described subject matteris well known and forms no part of the present invention, such matterbeing described only in sufiicient detail to provide a properunderstanding of the present invention. For more specific details of theabove subject matter, reference is made to my prior U.S. Letters PatentNo. 2,700,649.

Referring now to FIG. 3, the anode assembly 16 com prises in the formshown therein a plurality of vertically spaced anodes 3%) which are inelectrical contact with the cable 24 above referred to whereby apositive charge is maintained on the anodes. The anodes are secured tothe cable 24, preferably by telescopically mounting the anodesthereover, by any suitable means forming no part of the invention.

The anodes Sil and cable 24 are encased by a stranded plastic rope ormesh 32 which tightly contacts the surfaces of the anode and the cablewhereby the cable and anode are supported as well as encased by theplastic rope. To enhance the contact between the rope and the anodes andcable, the rope is preferably under tension. This can be accomplished byentirely or partially suspending the anode assembly by the plastic rope,although it will be apparent that such tensioning could also be providedmerely by tying the upper end of the rope to a fixed point and lettingthe weight of the anodes effect a tightening of the rope around theanode and cable. The rope is knotted as shown at 34 beneath the bottomanode in order to maintain the rope in its encasing position.

The rope 32 is highly flexible, both in a vertical and in a horizontaldirection, and is adapted tightly to engage the anodes and cable encasedthereby, being in the form of a tubular net sleeve which is contractibleupon application of tension longitudinally thereof. Thus, in thatportion of the rope encasing the anodes 30, the woven 3 =3 rope strandsare relatively far apart whereas the rope strands encasing the cable 24are relatively close together. The flexibility of the rope and thestranding method employed enable such a strand spacing to be achieved.It will be noted that due to the relatively distant spacing of the ropestrands encasing the anodes 30 the surface area of the anodes in contactwith the water is not materially decreased.

Although any plastic rope possessing the required characteristics willbe suitable for the use intended, highly satisfactory results have beenobtained through the use of polyethylene and polypropylene.

It will thus be seen that due to the flexibility of the rope 32 as abovedescribed and the ability of the same to contract and tightly to contactthe surfaces of the anodes, the encasement of the anodes by the strandedrope will have a strong tendency to retain the pieces of thedisintegrating anodes as Well as to prevent premature separation thereofinto such pieces. As previously mentioned, such rope may support theanodes or share such supporting function with the cable, and this may beof considerable benefit when an extra load is imposed thereon due to iceformation in the tank.

An alternative rope arrangement is shown in FIG. 4, the rope32 encasingonly the anodes 3t and not the cables 24, as shown in FIG. 3. In theFIG. 4 form, the anode assembly is'preierably suspended by means of thecable 24 and the upper end of the rope is tied to any suitable means(not shown).

In FIG; 5 there is shown a further embodiment of the novel anode'casingand support comprising the invention. The anode assembly of FIG. 5comprises a pair of hollow anode sections 35 which are secured togetherat their adjacently disposed ends preferably by means of a threaded boltconnection. Rope 32 is encased in strand form around each section withthe adjacent rope ends tied together in a knot 36 adjacent the joint ofthe anode sections 35. An insulated submarine cable 381s electricallyconnected to the upper end of the upper anode section 35 for providingcurrent to the anode sections. The upper end of the stranded rope'may betied as shown to the cable 38. In this form the entire anode assembly issuspended by means of the cable 38 in the same manner as describedabove.

The anode supporting ropes of FIGS. 4 and 5 function similarly to theFIG. 3 form in that they tightly contact the anodes to inhibit prematuredisintegration and prevent the undesirable dropping of pieces to thebottom of the tank.

It will thus be seen that the present invention provides a novel, highlyeffective means foreliminating the undesirable dropping of pieces ofdisintegrated anodes to the tank bottom. The flexibility of the plasticrope anode support enables the same to cheese and tightly contact avariety of anode shapes and diameters.

Other modes of applying the principle of the invention may beemplo'yed,change'being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

1 therefore particularly point out and distinctly claim as my,invention:

1. In a metal water tank having a plurality of elongated anodesvertically suspended in said tank and disposed on a common verticalaxis, and a source of direct electric current for maintaining a positivecharge on said vertically spaced anodes and a negative charge on saidtank; stranded flexible plastic rope means encasing said verticallyspaced anodes, said plastic rope means being vertically andhorizontally. extensible and tightly contacting said anodes whereby saidrope means serves to inhibit dropping of pieces of such anodes upondisintegration of the latter.

2. The combination of claim 1 wherein said anodes are vertically spacedand separated by an electric cable, said stranded plastic rope encasingboth said anodes and said cable.

3. The combination of claim 2 wherein said anodes are partiallysuspended by said stranded plastic rope and partially suspended by saidelectric cable.

4. The combination of claim 1 wherein said anodes are vertically spacedand are mounted on an electric submarine cable, and wherein said plasticrope encases only said anodes.

5. The combination of claim 1 wherein said anodes are hollow anddirectly connected at their opposed ends.

6. In a cathodic protection system including an anode suspended in abody of liquid, a flexible, vertically and horizontally extensible wovenplastic net closely fitting and encasing said anode whereby said plasticnet serves to inhibit dropping of pieces of such anode upondisintegration of the latter.

7. The system of claim 6, including means for applying tension to saidnet longitudinally of said anode to contract said net tightly about saidanode.

8. In a cathodic protection system for preventing tank corrosioncomprising an anode connected to a current source, supporting means forsuspending said anode in said tank, a supporting container of verticallyextensible and horizontally contractible, electrically non-conductivematerial around said anode, means separate from said first recitedsupporting means for suspending said container in said tank tightlycontacting said anode, said container being'extensively apertured forreadily permitting passage therethrough of the liquid within the tankfor contact with the surface of the anode, said container beingcontractibly movable relative to said anode thus actively initially andcontinually gripping and holding said anode to inhibit dropping offragments thereof upon progressive disintegration of the latter.

References Cited by the Examiner UNITED STATES PATENTS WINSTON A.DOUGLAS, Primary Examiner. JOHN H. MACK, MURRAY TILLMAN, Examiners.

1. IN A METAL WATER TANK HAVING A PLURALITY OF ELONGATGED ANODESVERTICALLY SUSPENDED IN SAID TANK AND DISPOSED ON A COMMON VERTICALAXIS, AND A SOURCE OF DIRECT ELECTRIC CURRENT FOR MAINTAINING A POSITIVECHARGE ON SAID VERTICALLY SPACED ANODES AND A NEGATIVE CHARGE ON SAIDTANK; STRANDED FLEXIBLE PLASTIC ROPE MEANS ENCASING SAID VERTICALLYSPACED ANODES, SAID PLASTIC ROPE MEANS BEING VERTICALLY AND HORZONTALLYEXTENSIBLE AND TIGHTLY CONTACTING SAID ANODES WHEREBY SAID ROPE MEANSSERVES TO INHIBIT DROPPING OF PIECES OF SUCH ANODES UPONDISINTEGRATIONOF THE LATTER.